Catalytic muffler embodying internal reservoir



Dec. 6, 1966 w. F. MALKIEWICZ 3,

CATALYTIC MUFFLER EMBQDYING INTERNAL RESERVOIR 2 Sheets-Sheet 1 Filed Aug. 22, 1963 INVENTOR. vl ds/aw ff/Q/Xzewzkz.

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CATALYTIC MUFFLER EMBODYING INTERNAL RESERVOIR Filed Aug. 22, 1963 2 Sheets-Sheet Z v. INVENTOR my .52! Mia/ 52w fw/ewaz 3,290,121 CATALYTIC MUFFLER EMBODYING INTERNAL RESERVOIR Wladyslaw F. Malkiewicz, Jackson, Micl1., assignor to Walker Manufacturing Company, a corporation of Delaware Filed Aug. 22, 1963, Ser. No. 303,785 6 Claims. (Cl. 23288) My invention relates to exhaust gas systems for internal combustion engines and has particular reference to an exhaust gas purifier that is especially adapted for use with diesel engines, such as those used in trucks.

It is an object of the invention to provide a catalytic converter for the exhaust gas system of an internal combustion engine that will burn-up and remove smoke and smog forming constituents that are unburned in exhaust gases as they leave the engine.

The invention accomplishes the foregoing and other objects by means of a relatively simple construction which utilizes a radial flow catalyst bed. The construction is such that it may be manufactured by means of manufacturing techniques developed in the automotive and truck mufller' field. The converter construction is such that it will withstand high temperatures and have a relatively long, useful life. A special feature of the invention comprises the inlet end construction of the converter which is designed to .have a bridge reinforcement and which is of such a nature that it may be readily adapted in the manufacturing stages to different applications without the necessity of making different parts.

The invention is illustrated in the accompanying drawings in which:

FIGURE 1 is a longitudinal cross section through a catalytic converter in accordance with the invention;

FIG. 2 is a cross section along the line 2-2 of FIG. 1;

FIG. 3 is an end elevation taken from the left of FIG. 1;

FIG. 4 is an end elevation taken from the left of FIG. 1;

FIG. 5 is a partial view in cross section of the louvers used in the catalyst chamber; and

FIG. 6 is a view taken at right angles to FIG. 4.

The exhaust gas converter and purifier 1 has an outer shell 3. A double layer 5 of creped or indented asbestos is preferably wrapped around the shell 3 and this is held in place by an outermost cover layer 7. The outer shell Uni ssfims; P

is preferably circular and concentric with its axis is an inner shell 9. Concentric with the outer shell 3 and the inner shell 9 is a center tube 11. A partition 13 is spotwelded and closes the left (top) end of the center tube.

The left end of the inner shell 9 terminates in substantially the same radial plane as the left end of the outer shell 3. The end of the inner shell 9 is closed by a partition 15 which has an annular flange 17 fitting inside the end of the tubular shell 9. Fitting around the outside of the end of the shell 9 is a ring-like partition 19 which has an inner flange 21 that is spotwelded to the end of the shell 9 and to the flange 17. The partition 19 has an outer flange 23 which is spotwelded to the end of the outer shell 3.

The right end of the inner shell 9 is closed by an annular partition 29 that has an outer annular flange 31 that fits inside the end of the shell 9. The partition 29 has an inner annular flange 33 and this fits around the outside of a bushing 35 which in turn is slipped over the end of the inner tube 11. There is a second annular par- 3,290,121 Patented Dec. 6,. 1966 tition 37 that Has an annular flange 39 that fits on the outside of the end of the tube 9and is spotwelded to' it and to the flange 31. The partition 37 has an outer an nular flange 41 which is spotwelded to the shell 3. The innertubell has a slip fit inside the bushing 35 to permit relative longitudinal movement.

There are two additional annular partitions 45 and 47 between the inner shell 9 and the center tube 11. These have outer annular flanges 49 and 51 which fit on the inside of the outer shell 9 and are spotwelded to it. They also have inner annular flanges 53 and 55 which fit around the center tube 11 but are not spotwelded to it so that the center tube can move longitudinally with respect to the partitions 45 and-47 as well as bushing 35. As seen in FIG. 2, the partitions 45 and 47 have a large number of relatively large openings 56 in them.

Preferably in the same radial plane as the partitions 45 and 47 are two additional annular partitions 57 and 59 between the inner shell 9 and the outer shell 3. The partitions 57 and 59 have inner radial flanges 61 and 63 which are spotwelded to the shell 9 and to the flanges 49 and 51. The partitions 57 and 59 also have outer annular flanges 65 and 67 which are spotwelded to the outer shell 3. The partitions 57, 59, and 37, as seen 11 FIG. 2, have a series of relatively large openings 69 therein.

It will be seen that there is a closed chamber 71 between the tube 11 and the inner shell 9 and a second chamber 73 between the inner shell 9 and the outer shell 3. The shell 9' and the inner tube 3 are both provided with a large number of fine flat louvers 75, as shown in FIGS. 6 and 7, so that gas can flow from the center tube 11 through the space 71 and into the space 73. The chamber 71 is filled with catalyst material of a suitable type. Thus, the space 71 forms a catalyst bed in which the exhaust gases are purified prior to entering the annular outlet chamber 73. The converter 1 is mounted with its longitudinal axis vertical and with catalyst-filled end space 76 on top so that it will act as a reservoir from which catalyst flows to fill the bed 71.

In order to promote a uniform gas flow radially through the bed 71, the inner tube 11 is preferably provided with a series of internal partitions 77, 79, 81 and 83. These have openings in them of progressively decreasing diameter so as to impose an increasing resistance to flow and thus counteract the normal tendency of gas entering the tube 11 to pile-up at the left end of the tube.

The right hand end of the converter 1, as seen in FIGS. 1. and 4, has a novel construction which includes a partition or header that has an annular outer flange 97 which is spotwelded to theinside of the end of the shell 3. Spaced longitudinally inwardly from the header 95 is apartition 99 that has an annular flange 101 which is spotwelded to the inner shell 3. The partition 95 has an annular neck 103 in which a large inlet bushing 105 is supported and spotwelded. The inner end of the inlet bushing 105 is welded at 107 to the partition 99. The bottom side of the bushing 105 is slit axially along a line 109 and then along a pair of radial lines 111. This forms two cars 113 which are then bent away from each other along a bend line 115. These ears fit on the outside of an extended part 116 of the bushing 35 and are spotwelded or are welded: to it. The bushing 35 fits inside and is spotwelded to a flange 117 on the partition 99 and the upper portion thereof terminates at the partition 99.

However, the lower portion 116, as seen in FIG. 1, ex-

tends to the end of the ears 113 and the opening which would otherwise be present between the bottom of the bushing 35 and the bottom of the bushing 105 is closed by the partition 119 which has the flange 121 spotwelded inside the end of the bushing 35 extension.

The header 95 and the partition 99 have aligned flanged necks 125 and 127 and these receive and are spotwelded to an outlet tube 129. The outlet tube opens into the space 131 between the partition 37 and the partition 99. Inasmuch as the partition 37 has the holes 69 in it, gas in the chamber 73 can flow into the chamber 131 and then into the outlet tube 129.

Inlet gas entering the large inlet tube 105 deadends against the section 133 of the partition 99 and therefore must flow into the tube or bushing 35 and thence into the center louver tube 11 from which it flows radially through the catalyst bed and then into the outlet chamber 73.

It will be noted that the structure at the right hand end of the converter 1 is such that different angular positions of the inlet and outlet bushings 105 and 129 can be readily obtained merely by rotating the header 95 and the partition 99 to the desired position before spotwelding them in place. The header 95 is bridge-reinforced against excessive pressures inside the converter and against blowout by means of the two bushings 105 and 129 which are spotwelded to it and to the internal partition 99, which in turn is spotwelded to shell 3.

The catalyst bed 71 and reservoir 76 may be replenished by removing a plug or fitting 135 in the top partition 15. A catalyst drain and fill tube 137 may be spotwelded at opposite ends in suitable flanges in the partition 29 and in the header 95 and closed by a suitable fill plug 139. If the fill tube 137 is used, then the partition 29 will, of course, be rotated at assembly of the converter so that its aperture to receive the tube 135 is in alignment with the corresponding aperture on the head 95.

In use, it is contemplated that the longitudinal axis of the converter will be vertical with the reservoir 76 on top. Reservoir 76 and bed 71 are filled with a suitable catalyst. Inlet bushing 105 is attached to the exhaust pipe from the diesel engine and outlet 129 to a tailpipe. Gas containing unburned constituents enters bushing 105 and flows through bushing 35 into louver tube 11. From tube 11 it flows radially outwardly, in a relatively uniform manner around and along the length of tube 11, through louvers 75 and catalyst bed 71, and through inner shell louvers 75 into annular outlet passage 73. As the unburned constituents are burned, heat is liberated in bed 71 but the slip fit of tube 11 accommodates diiferential expansions. Gas in passage '73 flows into chamber 131 and then out of the converter through outlet bushing 129.

I claim:

1. A catalyst convertor for reducing the smog producing constituents of the exhaust gases of an internal combustion engine comprising a catalyst bed defined at least in part by a catalyst bed outer shell, a perforate catalyst bed inner shell extending within said catalyst bed outer shell and having one end thereof terminating at a longitudinally spaced distance from one end of said catalyst bed outer shell, means forming an imperforate closure for said one end of said-catalyst bed inner shell and means forming closures for the opposite ends of said catalyst bed, an outer housing for said catalyst convertor for containing said catalyst bed and defining a space therebetween, said outer housing including means defining an exhaust gas inlet and an exhaust gas outlet for said catalyst convertor, one of said exhaust gas inlet and said exhaust gas outlet being in fluid communication with said catalyst bed inner shell, the other of said exhaust gas inlet and Said exhaust gas outlet means being in communication with the space between said catalyst bed outer shell and said outer housing, and a plurality of perforations in said catalyst bed outer shell for radial exhaust gas flow through the catalyst bed defined by said catalyst bed inner and outer shells and said closure means, said catalyst convertor being positioned in use in a substantially vertical position, the volume between said one end of said catalyst bed inner shell and the adjacent closure means of said catalyst bed outer shell functioning as a catalyst reservoir for gravity flow of catalyst from said reservoir into the volume between the perforate portions of said catalyst bed inner and outer shells, the catalyst bed components defining said volume being imperforate.

2. A catalyst convertor for reducing the smog producing constituents of the exhaust gases of an internal combustion engine comprising an outer shell, a catalyst bed supported within said outer shell and defining a space therebetween, said catalyst bed being comprised of a perforate catalyst bed outer shell, a perforate central gas flow tube supported within said catalyst bed outer shell and means forming closures for opposite ends of said catalyst bed, one end of said central tube being opened through one end of said catalyst bed for forming a gas flow passage for said catalyst bed, an end header closing the end of said outer shell adjacent said one end of said central tube, means closing the other end of said outer shell, a first exhaust gas bushing supported by said end header, said first exhaust gas bushing being offset from said central gas flow tube whereby said first bushing and said central tube are eccentrically disposed with respect to each other, a major portion of the cross-sectional area of said first exhaust gas bushing and a major portion of the cross-sectional area of said central tube lying in overlapping relationship, means forming a closure for the adjacent non-overlapping portions of said exhaust gas bushing and said central tube, and a second exhaust gas bushing supported by said end header and communieating at one end thereof with the space between said catalyst bed outer shell and said outer shell.

3. A device as set forth in claim 2 wherein the end of the central tube opposite to the end header terminates at a spaced location from the adjacent end of the catalyst bed outer shell for forming a catalyst reservoir in the space therebetween, said device being positioned in use in a vertical direction with the end header at the lower end thereof whereby catalyst may flow from said catalyst reservoir into the remainder of the catalyst bed by gravity.

4. A device as set forth in claim 2 wherein a plurality of longitudinally spaced reinforcing members extend between the catalyst bed outer shell and the outer shell, a plurality of longitudinally spaced reinforcing members extend between the catalyst bed outer shell and the central tube, each of said reinforcing members having flow openings formed therein, at least one group of said reinforcing members being afl'ixed at one end thereof to the adjacent component and slidably guiding the other component at its other end for permitting relative thermal expansion.

5. A device as set forth in claim 2 wherein the end header is symmetric about at least one longitudinally extending plane for assembly of the end header to the outer shell in one of at least two relative angular positions, said central tube and said first bushing being eccentrically disposed in each position and overlapping in each position.

6. A device for the exhaust gases of an internal com bustion engine comprising an outer shell, a central gas flow tube supported within said outer shell, an end header closing one end of said outer shell, means closing the other end of said outer shell, an exhaust gas bushing supported by said end header, said exhaust gas bushing being offset from said central gas flow tube whereby said bushing and said central tube are eccentrically disposed with respect to each other, a major portion of the crosssectional area of said exhaust gas bushing and a major portion of the cross-sectional area of said central tube lying in overlapping relationship, means forming a closure for the adjacent non-overlapping portions of said 5 exhaust gas bushing and said central tube, a gas flow passage formed within said outer shell transversely outwardly of said central tube, and a second exhaust gas bushing mounted upon said header and communicating at one end thereof with said gas flow passage.

References Cited by the Examiner UNITED STATES PATENTS 1,875,024 8/ 1932 Kryzanowsky 23288 2,846,021 8/ 1958 Encinas.

3,041,149 6/1962 Houdry 23288 3,042,499 7/ 1962 Williams 23277 6 3,090,677 5/ 1963 Scheitlin et al. 23288 3,113,000 12/1963 Gerhold 23288 FOREIGN PATENTS 5 142,388 7/ 1935 Austria.

631,368 6/1936 Germany.

436,331 10/ 1935 Great Britain.

439,766 12/1935 Great Britain.

10 MORRIS O. WOLK, Primary Examiner.

J. SCOVRONEK, Assistant Examiner. 

1. A CATALYST CONVERTOR FOR REDUCING THE SMOG PRODUCING CONSTITUENTS OF TH EXHAUST GASES OF AN INTERNAL COMBUSTION ENGINE COMPRISING A CATALYST BED DEFINED AT LEAST IN PART BY A CATALYST BED OUTER SHELL, A PERFORATE CATALYST BED INNER SHELL EXTENDING WITHIN SAID CATALYST BED OUTER SHELL AND HAVING ONE END THEREOF TERMINATING AT A LONGITUDINALLY SPACED DISTANCE FROM ONE END OF SAID CATALYST BED OUTER SHELL, MEANS FORMING AN IMPERFORATE CLOSURE FOR SAID ONE END OF SAID CATALYST BED INNER SHELL AND MEANS FORMING CLOSURES FOR THE OPPOSITE ENDS OF SAID CATALYST BED, AN OUTER HOUSING FOR SAID CATALYST CONVERTOR FOR CONTAINING SAID CATALYST BED AND DEFINING A SPACE THEREBETWEEN, SAID OUTER HOUSING INCLUDING MEANS DEFINING AN EXHAUST GAS INLET AND AN EXHAUST GAS OUTLET FOR SAID CATALYST CONVERTOR, ONE OF SAID EXHAUST GAS INLET AND SAID EXHAUST GAS OUTLET BEING IN FLUID COMMUNICATION WITH SAID CATALYST BED INNER SHELL, THE OTHER OF SAID EXHAUST GAS INLET AND SAID EXHAUST GAS OUTLET MEANS BEING IN COMMUNICATION WITH THE SPACE BETWEEN SAID CATALYST BED OUTER SHELL AND SAID OUTER HOUSING, AND A PLURALITY OF PERFORATIONS IN SAID CATALYST BED OUTER SHALL FOR RADIAL EXHAUST GAS FLOW THROUGH THE CATALYST BED DEFINED BY SAID CATALYST BED INNER AND OUTER SHELLS AND SAID CLOSURE MEANS, SAID CATALYST CONVERTOR BEING POSITIONED IN USE IN A SUBSTANTIALLY VERTICAL POSITION, THE VOLUME BETWEEN SAID ONE END OF SAID CATALYST BED INNER SHELL AND THE ADJACENT CLOSURE MEANS OF SAID CATALYST BED OUTER SHELL FUNCTIONING AS A CATALYST RESERVOIR FOR GRAVITY FLOW OF CATALYST FROM SAID RESERVOIR INTO THE VOLUME BETWEEN TH PERFORATE PORTIONS OF SAID CATALYST BED INNER AND OUTER SHELLS, THE CATALYST BED COMPONENTS DEFINING SAID VOLUME BEING IMPERFORATE. 